Jeep running rough after it warms up


Mr Otis

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My 08 started running rough only after about 13 miles of driving. I pulled the codes and they were for egr valve and cyl 6 misfire. I changed the egr valve and both the plug and wire on cyl 6 as thats all i had time for. Could this possibly be a catalytic converter issue? It runs fine on a cold start in the morning but is rough running bye the time i get to work.
 

BLACKJKU

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I could have saved you some money if you posted earlier because I deleted my EGR valve over a year ago and the only issue I have from that is the stupid CEL. If your cat is bad you should get a CEL for a downstream O2 sensor. Did you put a OEM plug and wire on I know others who didn't on the plugs and they had to replace them because these Jeeps are picky on what goes on them.
 
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Mr Otis

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I put autolite double platinum plug in and ultima select wire. Yeah the egr was 100$ i didnt need to spend
 

BLACKJKU

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I put autolite double platinum plug in and ultima select wire. Yeah the egr was 100$ i didnt need to spend

I don't know if you put the correct plug in or not was it the same part number as the one you took out? Ultima select doesn't sound like a OEM wire. How many miles on the Jeep? I take it you just bought the Jeep?
 
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Mr Otis

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Ive had the jeep for 5 yrs. has 171,000 on it, give or take with the 35" tires. I changed plugs, wites, and coil about a yr and a half ago when i was chasing a multi misfire that turned out to be the computer.
 

Craig T

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I had a misfire from a clogged cat. The engine ran fine unless I tried to accelerate too hard then it back pressured and misfired. That doesn’t sound like what your problem is.
 
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Mr Otis

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Have any luck getting it figured out?
I was able to get to the parts store and had them run the codes. Since All i was doin is with the key. I came up with. Several codes. P0052... Bank 2 upstream o2 sensor, so i changed both upstream sensors. P0300... multiplee cyl misfire. P0306.... Cyl 6 misfire. And P0206....fuel injector cyl 6. Which i have to wait til this weekend to get a noid light to check the electric pulse to. From what im reading the most common cause of the 0206 code is a bad injector. Whats got me is the 0300 code. Ladt time i got that code i had to get a pcm.
 
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Mr Otis

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I cleared the codes after doing bith o2 sensors and will recheck them this weekend. What sucks is this is my wifes daily. And my daily, 95 XJ is down with 2 dead cylinders.
 

MacGuyver

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I bring this up because you made a comment that implies you never fixed the speedometer after bigger tires. Just and annoyance if this is a manual, but if you have been running an automatic without fixing the speedometer that is more than an annoyance. Wranglers use the speedometer to determine shift points. Fix this asap if that is the case.
 
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Craig T

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So p0300 was what I was getting from a clogged cat. If I tried to accelerate too hard it would flash and go into limp mode. Also had O2 sensor codes. I tried the $25 cat cleaner stuff which did nothing. Changed out the cats it runs beautiful. One side was clear, this was the other.
C8BF6F50-0E29-4E10-896C-1CF5F971884A.jpeg
 
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Mr Otis

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I bring this up because you made a comment that implies you never fixed the speedometer after bigger tires. Just and annoyance if this is a manual, but if you have been running an automatic without fixing the speedometer that is more than an annoyance. Wranglers use the speedometer to determine shift points. Fix this asap if that is the case.
It is a manual. Ty for the info though
So p0300 was what I was getting from a clogged cat. If I tried to accelerate too hard it would flash and go into limp mode. Also had O2 sensor codes. I tried the $25 cat cleaner stuff which did nothing. Changed out the cats it runs beautiful. One side was clear, this was the other.
View attachment 118094
My new cats will be here monday hopefully. Im gonna repull codes Saturday and check the injector and wiring. Then do a comp test.
 

Craig T

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Enjoy the wrestling match replacing the cats. A couple hints: pull your front fenders off, much easier to access the bolts to the manifolds and disconnect the battery. I learned that second one the hard way as I hit the starter terminal putting in the new one.
927BB6AD-B223-4A2F-B74E-D3B17CB60CA1.jpeg
 
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